Centrifugal pump and automatic primer



Oct. 7, 1947. R. w. FERNSTRUM CENTRIFUGAL YUM P AND AUTOMATIC PRIMER Filed June 9, 1945 warm 5/52? I EMMY Patented Oct. 7, 1947 Robert W. Fernstrum, Detroit, Mich assignor to Marine Products Company, Detroit, Mich., a

corporation of Michigan AppllcationJune 9, 1945, Serial No. 598,435

11 Claims. 1

The present invention relates to centrifugal pumps of the volute casing type, and more particularly, to an automatic self-contained priming chamber therefor.

The primary object of the invention is to provide a centrifugal pump of the volute casing type with a priming chamber arranged to contain a quantity of liquid when the impeller of the pump has been brought to rest so that liquid will find its way to the pump chamber through a series of obliquely and tangentially arranged openings and thereby prime the pump in a minimum amount of time and with the least expenditure of energy.

Another object of the invention is to provide a centrifugal pump of the volute casing type with a priming chamber which is formed as part of the casing of the pump and is arranged to feed liquid to the pump impeller and pump chamber at a point in advance of the volute casing discharge passageway.

Another object of the invention is to provide a centrifugal pump of the volute casing type having a centrally arranged suction inlet and a peripherally arranged discharge opening disposed lowermost with respect to the volutecasing so that when the pump is brought to rest, a quantity of liquid will betrapped in the priming chamber as well as in the pump casing proper.

Another object of the invention is to provide a centrifugal pump of the volute casing type having its discharge disposed lowermost and communicating with the discharge nozzle through a vertically arranged passageway in which there is disposed a partition wall terminating adjacent the discharge nozzle and arranged with its lower end connected to the wall of the discharge opening so as to form a priming chamber between the volute casing and the partition wall to contain a quantity of liquid so that the liquid may be fed to the interior of the volute casing through a series of tangentially arranged apertures and thereby prime the pump when the same is set in operation.

Another object of the invention resides in constructlng the centrifugal pump in such a manner as to provide a central suction intake and a discharge which has its outlet communicating with the casing conduit arranged lowermost.

Another object of the invention is to provide a priming chamber in the casing of a centrifugal pump which is so arranged as to trap a quantity of liquid which is adapted to be fed to the pump chamber through a series of obliquely arranged openings'disposed in the direction of rotation oi the pump impeller and positioned adjacent the volute casing discharge opening.

Other objects and advantages of the inventio will become apparent during the course of the following description of the accompanying drawing, wherein:

Figure 1 is a vertical cross-sectional view taken on the irregular line 1-! of Figure 2 showing the general arrangement 'of the pump structure and the lower portion of the priming chamber with the obliquely arranged passageways connecting the priming chamber with the interior of the volute casing;

Figure 2 is a vertical cross-sectional view taken on line 2-2 of Figure 1 looking in the direction of the arrows and showing the general arrangement of the priming chamber and. structural details of the pump casing; and Y Figure 3 is a horizontal cross-sectional view taken on line 3--3 of Figure 2 looking in the direction of the arrows and'showing the vertically arranged pump discharge which is separated from the priming chamber by a central partition extending through the discharge passageway.

In the drawing, attention is first directed to Figure 1 wherein there is shown a base 5 having an integrated structure 6 which is termed to provide a bearing boss 1 having a bearing opening 8. A shaft 9 is rotatably mounted in the bearing boss 1 to rotate in the bearing opening 8 and is provided on one ,end with a pulley i0 having avV- may be keyed to the shaft or otherwise secured thereto. A shaft packing I5 is bolted in place by means of a pair of bolts 16 disposed on diametrically opposite sides of the'shaft 9 and is adapted to be held in place by retaining nuts I! on the bearing boss I.

The impeller blades extend from a point slightly spaced from the center of. the disc l3 as at. It and terminate adjacent the peripheral surface of the disc IS.

The pump casing is formed with a front wall 20 having'relatively straight side walls 2| and 22 connected to the bottom by an arcuately curved bottom wall'23. Also formed integral with the front wall of the casing 20 is a top wall 2 which connects the upper end of the side walls 2i and 22. Inlet and outlet connections 26 and 2] are formed with threaded openings 28 and 29 respectively and are provided in the top wall 24 as shown clearly in Figure 2. l

Formed within the pump casing is a volute casing 30 which extends irom a position adjacent the lowermost portion of the curved bottom wall 23 as at 3| and terminates in a juncture with the side wall 22 as at 32. The volute casing is formed integral with a partial rear wall 33 which is provided with an opening 34 and terminates in an enlarged beaded portion 35. The annular fiange l2 of the disc-like plate i I is adapted to be received in the opening 34 in the rear wall 33 and bolts or the like .as at 38 may extend through suitable openings in the disc-like casting so as to bereceived in threaded openings 33 in the annular boss 35. When the pump casing above described is fastened to the disc-like casting H, the impeller disc assumes a position with respect to the volute casing 30 so as to position said impeller with respect to the casing in such a manner as to obtain the most eflicient operation of the centrifugal pump. The volute casing 30 is provided "with an interior wall 39 having an opening 40 which is adapted to communicate with the intake connection 26 through a chamber 4| so that fluid, will be fed to the suction side of the pump through the opening 2|. A partition wallAZ connects the interior wall 39 of the volute casing with the front wall 20 of the pump casing so as to block off the inlet chamber 4| from the remaining portion of the pump chamber. It is also to be noted that the inlet connection 23 and the outlet connection 21 are divided by a short partition wall 43 which connects with the volute casing 30 and extends downwardly on one side of the opening 40 and is integrated with the interior wall 39 of the volute casing so as to connect with the short wall 42, and likewise connects with the front wall 20 of the pump casing. Thus, the short wall 43 and the remaining portion thereof extending on one side of the opening 40 and integrated with the rear wall 39 of the volute casing, forms on the other side thereof between the volute casing 30 and straight wall portion 2| of the pump housing or casing, an outlet or discharge passageway 44 which has its lower end in communication with the discharge opening in the volute casing 30 between the peripheral portion 3| of the volute casing and the arcuately curved bottom wall 23 of the pump casing.

Extending between the front wall 20 of the pump casing and the partial rear wall 33 thereof in the exhaust passageway 44 is an arcuately curved partition wall 45 which is integrated with the volute casing 30 as at 3| and has its upper end terminating as at 46 a short'distance from the exhaust coupling or connection 21. The partition wall 45 thus divides the exhaust passageway 44 and forms between the volute casing 30 and 'said partition a priming chamber 41.

A series of obliquely arranged passageways 43 is formed in the peripheral surface of the volute casing 30 and extends tangentially with respect to the impeller disc I3. The openings or passageways 48 are formed in the lowermost portion of the volute casing 30 in spaced relation from the juncture of the partition wall 45 therewith as at 3|. It is also to be noted that the portion of the volutecasing 20 in which the obliquely arranged passageways 48 are disposed is slightly enlarged as at 49 to provide a stepped surface connecting the'volute casing 30 and the point 3| which has its inner surface in contiguous relation with the end surfaces of the impeller blades [4. It has been found that better results are obtained andv that the pump may be primed in a reasonably short period of time by providing the stepped surface 50 between the volute casing 30 and the point 3| thereof adjacent the discharge of the pump.

Also, it has been found that with the arrangement of the oblique passageways 48 such that a 4 they are disposed tangentially in the direction of rotation of the impeller, better results will be accomplished and the time required for priming the pump will be greatly decreased.

- Operation The base 5 may be mounted on a suitable support and secured thereto by anchoring the same in place so that a motor may be drivingly connected with the pulley ID by means of a suitable V, belt; The inlet connection 26 is connected with a source of liquid and the outlet connection 21' i will be trapped in the priming chamber 41 while the pump is continually forcing liquid through the discharge passageway 44. When the pump is stopped, and if th source of liquid is below the, level of the pump, the pump casing will drain until partially filled with liquid in the lower portion thereof by reason of the fact that the liquid trapped in the priming chamber 41 will find its way into the pump chamber through the obliquely arranged passageways 48. When' the pump is again started, the trapped liquid will be forced upwardly through the passageway '44 and will flow into the priming chamber 4'! .and thence into the pump chamber formed by the volute casing through the obliquely arranged openings or passageways 48. Circulation will continue until all of theair is dispersed through the liquid from the suction side of the pump, after which the ,gliquid will be drawn up to the level of the pump intake and will thus be primed for pumping action.

It is to be noted that the volute casing 30 and curved wall '23 of the pump casing form a spiral, since the volute casing 30 is integrated with the curved bottom wall 23"and relatively spaced side wall 22 as at 32 to form a volute casing in which the discharge is lowermost and which is of a design to produce the most eflicient operation.

It will thus be seen that during priming, the trapped liquid will be pumped through the passageway 44 and over the top of the partition 45 as at 46 soas to be drawn into the pump chamber through the passageways 48 after the air has been dispersed and has passed through the discharge pipe connection 21. The slight clearance between the step 50 and the eripheral edges of the impeller blades I4 reduces the pressure in the priming chamber 41 so that the liquid will be drawn through the obliquely arranged openings or passageways 48 in a continuous flow stream rather than one which is interrupted each time the peripheral edge of the blade passes thereover.

It is to be understood that the form ofthe invention herewith shown and described is to be taken as a preferred embodiment thereof and that various changes may be made in the shape, size and arrangement of parts without departing from the spirit of the invention or the scope of the subjoined claims.

What I claim is:

1. A centrifugal pump comprising a pump cas ing having an impeller chamber therein. an impeller rotatably mounted in said impeller chamber, said casing having an inlet passageway opening into said impeller chamber and a. discharge passageway opening out of the bottom portion of said impeller chamber and extending upward therefrom, and an upwardly extending priming chamber disposedadjacent said impeller chamber, said priming chamber having its upper portion communicating with said discharge passageway and havinga priming port extending from its lower portion into said impeller chamber.

2. A centrifugal pump comprising a pump casing having an impeller chamber therein, an impeller rotatably mounted in'said impeller chamber, said casing having an inlet passageway opening into said impeller chamber and a discharge passageway opening out of the bottom portion of said impeller chamber and extending upward therefrom, and an upwardly extending priming chamber disposed adjacent said impeller chamber, said priming chamber having its upperportion communicating with said discharge passageway and having a priming port extending from its lower portion into said impeller chamber, said priming port being arranged obliquely to the radius thereto of said impeller,

3. A centrifugal pump, comprising a casing having a curved wall portion, a spiral wall connected to said casing and merging with the curved wall portion thereof to provide a volute pump chamber, said volute pump chamber being arranged obliquely with respect to the radiusthereto of said impeller and extending inwardly in the direction of rotation thereof.

4. A centrifugal pump comprising a pump casing having an impeller chamber therein, an impeller rotatably mounted in said impeller chamber, said casing having an inlet passageway opening into said impeller chamber and a discharge passageway opening out of the bottom portion of said impeller chamber and extending upward therefrom, and an upwardly extending priming chamber disposed adjacent said impeller chamber, said priming chamber having its upper portion communicating with said discharge passageway and having a priming port extending from its lower portion into said impeller chamber, said priming ort being arranged obliquely to the radius thereto of said impeller and extending inward in the direction of rotation of said impeller.

5. A centrifugal pump comprising a pump casing having an impeller chamber therein, an impeller rotatably mounted in said impeller chamber, said casing having an inlet passageway opening into said impeller chamber and a discharge passageway opening out of the bottom portion of said impeller chamber and extending upward therefrom, and an upwardly extending priming chamber disposed adjacent said impeller chamber, said priming chamber having its upper portion communicating with said discharge passageway and having a'priming port extending from its lower portion into said impeller chamber,the

interior surface of said impeller chamber adiacent the outlet of said priming ort being stepped back from the periphery of said impeller to provide clearance between said outlet and said impeller.

6. A centrifugal pump, comprising a casing having side and end walls connected by a curved bottom wall, a rotary shaft extending into said sageways formed in said casing communicating respectively with the suction and discharge openings in said volute pump chamber, and a partition wall connected with the spiral wall of said volute pump chamber adjacent said volute pump chamber discharge opening and extending through said discharge passageway to divide said passageway and form a priming chamber between the partition wall and spiral wall of said volute pump chamber, said spiral wall being provided with a series of ports connecting the priming chamber with the volute pump chamber adjacentsthe discharge opening of said volute casing, and said ports being arranged obliquely with respect to the radius thereto of said impeller and extending inward in the direction of rotation of said impeller.

7. A centrifugal pump, comprising a casing having side and end walls connected by a curved bottom wall, a rotary shaft extending into said casing through one of the side walls thereof and disposed eccentrically with respect to said curved bottom wall, a spiral wall connected to one of said side walls and merging with one of said end walls to form a continuation of said curved bottom wall and provide a volute pump chamber within said casin suction and discharge openings for said volute pump chamber, an impeller mounted on said rotar shaft to rotat within said pump chamber, inlet and discharge passageways formed in said casing communicating respectively with the suction and discharge openings in said volute pump chamber, and a partition wall connected with the spiral wallof said volute pump chamber adjacent said 'volute pump outlets of said ports from the peripheral edge of said impeller.

8. In a centrifugal pump having a volute pump casing having suction and discharge openings and an impeller rotatably mounted therein, a. discharge passageway connected to said discharge opening, an upwardly-extending priming cham- .ber associated with said discharge passageway and arranged to entrap liquid passing from said discharge opening, and a series of ports extending from the lower portion of said prim-' ing chamber into said volute pum casing for amass? I 7 connecting said priming chamber with said volute pump casing adjacent the discharge opening thereof. i

9. In a centrifugal pump including a volute pump casing having suction and'discha'rge openings and an impeller rotatably mounted therein, a priming chamber associated with said pump casing and arranged to entrap liquid passing from said discharge opening, and a series of portsin said volute pump casing for connecting said priming chamber with said volute pump casing adja-- cent the discharge opening thereof, said ports being arranged obliquely and extending inward in the direction of rotation of said'impelier.

10. In a centrifugal pump including a volute casing having suction and discharge openings and an impeller rotatably mounted therein, a priming chamber associated with saidpump casing and arranged to entrap liquid passing from said discharge opening, and a series of ports in said volute pump casing adjacent the discharge opening thereof, said ports being arranged obliquely and extending inward in the direction'of rotation of said impeller, the interior surface of said volute casing adfacent the ports being stepped'to proports and said impeller.

' vide clearance between the outlet sides of said 11. In a centrifugal pump including a volute casing having suction and discharge openings and an impeller rotatabiy mounted in said casing, a Priming chamber connected to said volute casing arranged to entrap liquid'fro'm said discharge opening, and a series of ports in the volute cas-- ing adjacent the discharge opening thereof for communicating the liquid trapp d in said priming chamber with the interior of said volute pump casing. said ports being obliquely arranged and extending inward in the direction of rotation of said impeller.

ROBERT W. FERNS'I'RUML REFERENCES CITE!) The following references are of record in the tile of this patent:

Mueller Feb. 12, 1946 

